Variations of tool and task characteristics reveal that tool-use postures are anticipated

The authors examined anticipation in tool use, focusing on tool length and tool-use posture. Adults (9 women and 9 men in each experiment) held a rod (length 0.4-0.8 m), with the tip upward; walked toward a cube; chose a place to stop; and displaced the cube with the rod's tip. In 2 experiments, rod length, mass, and mass distribution, and the size of the cube were manipulated. Chosen distance depended on rod length and cube size. Because effects of cube size on distance resulted only from postural changes related to required control, distance anticipated displacement posture. A postural synergy comprising legs and trunk provided a stable platform for the displacement. An arm synergy was less extended for small cubes, longer rods, and handle-weighted rods. Selected distance anticipated those postures.     

Geometrics and dynamics of a rod determine how it is used for reaching

Displacing an object with a hand-held rod provided a simple paradigm for studying tool use. The authors asked how reaching was affected by manipulations of rod properties. Adults held a rod (length =.10 to 1.5 m), with its tip in the air; walked toward an object on a table; chose a place to stop; and displaced the object with the rod's tip. In 3 experiments (Ns = 9, 22, and 17 participants), the authors manipulated rod length, mass, and mass distribution to determine whether and how geometric and dynamic properties affected the chosen distance and the posture. Both the chosen stopping distance and the postures were well accommodated to rod characteristics. Postural adaptations took place only in the arm, which was organized as a synergy. Predictably, rod length explained most of the variance, but small and reliable differences in both distance and posture depended on mass and mass distribution. The chosen distance anticipated not only rod length but also the upcoming posture needed to control the rod.     

Maternal attachment representations after very preterm birth and the effect of early intervention

Objective

For very preterm infants the mother-infant relationship may be compromised. Maternal attachment representations 18 (corrected) months after very preterm birth and the effect of the post-discharge Infant Behavioral Assessment and Intervention Program (IBAIP) were studied. The IBAIP is designed to assist parents to support and enhance their infant's regulatory competence and development. The intervention consisted of 6-8 home visits during the first 8 months after birth.

Method

Seventy-eight mothers of very preterm infants (<32 weeks and/or <1500 g) were interviewed, who participated in a randomized controlled trial: 41 from the intervention group and 37 from the control group. Maternal attachment representations were assessed with the Working Model of the Child Interview (WMCI). The interviews resulted in a classification of the attachment representations into balanced or non-balanced.

Results

30% of the mothers had non-balanced attachment representations. Qualitative content analysis of the answers showed that negative feelings when first seeing their baby and negative or ambivalent feelings in the first weeks at home with their baby are related to non-balanced attachment representations. The WMCI revealed no differences between the intervention and control group.

Conclusion

Early support for mothers of very preterm born infants to develop a healthy mother-infant relationship is recommended especially for mothers who report negative first experiences.     

Advancing an Understanding of the Anxiety Control Questionnaire for Children (ACQ-C) in Clinically Anxious and Non-Anxious Youth: Psychometric Properties,Incremental Prediction and Developmental Differences

A lack of perceived control over anxiety-related situations is theorized to be characteristic of anxiety disorders in children and adolescents. In the current study we tested several theoretical predictions and developmental variation with the Dutch translation of the Anxiety Control Questionnaire for Children (ACQ-C). The theoretical factor structure of anxiety control was tested using Confirmatory Factor Analysis (CFA) in 548 non-referred children (8–18 years old, M?=?12.5 years; 50.7 % girls). The incremental predictive validity of perceived control for anxiety status was assessed using logistic regression in 141 clinically anxious children (age M?=?12.6 years; 56.7 % girls) and 298 non-referred non-anxious children (age M?=?12.6 years; 52.7 % girls). CFA showed that both a one-factor model and two-factor model (perceived control over internal reactions and external events) fit well. The one-factor model proved invariant across age and gender. Internal consistency was excellent (Cronbach’s α?=?.93). Two-month test-retest reliability was adequate. The ACQ-C was able to incrementally predict diagnostic status, even after controlling for age, gender and self-reported anxiety symptoms. Finally, both younger children and girls reported less perceived control, independent of anxiety level. Findings advance the understanding of the psychometric properties of the ACQ-C, the role of control in childhood anxiety and point to the potential utility of the ACQ-C in both clinical and community samples. The Dutch translation of the ACQ-C demonstrated sound psychometric properties.     

Geometries and Dynamics of a Rod Determine How It Is Used for Reaching

Displacing an object with a hand-held rod provided a simple paradigm for studying tool use. The authors asked how reaching was affected by manipulations of rod properties. Adults held a rod (length = .10 to 1.5 m), with its tip in the air; walked toward an object on a table; chose a place to stop; and displaced the object with the rod's tip. In 3 experiments (Ns = 9, 22, and 17 participants), the authors manipulated rod length, mass, and mass distribution to determine whether and how geometric and dynamic properties affected the chosen distance and the posture. Both the chosen stopping distance and the postures were well accommodated to rod characteristics. Postural adaptations took place only in the arm, which was organized as a synergy. Predictably, rod length explained most of the variance, but small and reliable differences in both distance and posture depended on mass and mass distribution. The chosen distance anticipated not only rod length but also the upcoming posture needed to control the rod.     

Dynamic time warping: a new method in the study of poor handwriting

Poor handwriting is a diagnostic criterion for developmental coordination disorder. Typical of poor handwriting is its low overall quality and the high variability of the spatial characteristics of the letters, usually assessed with a subjective handwriting scale. Recently, Dynamic Time Warping (DTW), a technique originally developed for speech recognition, was introduced for pattern recognition in handwriting. The present study evaluates its application to analyze poor handwriting. Forty children attending Dutch mainstream primary schools were recruited and based on their scores on the Concise Evaluation Scale for Children's Handwriting (Dutch abbreviation: BHK), 20 good and 20 poor writers (of whom 13 were scheduled for handwriting intervention) were identified. The groups were matched for age (7-9 years), school grade (grades 2 and 3) and handedness. The children subsequently wrote sequences of the letter "a" on a graphics tablet in three conditions (normal, fast, and accurate). Classical kinematics were obtained and for each individual letter DTW was used to calculate the distance from the mean shape. The DTW data revealed much higher variability in the letter forms of the poor writers that was independent of the kinematic results of larger trajectories, faster movements, and higher pen pressure. The current results suggest that DTW is a valid and objective technique for letter-form analysis in handwriting and may hence be useful to evaluate the rehabilitation treatments of children suffering from poor handwriting. In education research it may be exploited to explore how children (should) learn to write.     

Attention-Deficit Hyperactivity Disorder (ADHD) Symptoms in Children Adopted from Poland and their Atypical Association Patterns: a Bayesian Approach

Although high rates of attention-deficit hyperactivity disorder (ADHD) symptoms have been observed among internationally adopted children, research on these symptoms in Polish adoptees is lacking. Therefore, we examined ADHD symptoms in Polish adoptees and their relationship to pre-adoptive risk factors, that is, time in institutional care, early deprivation, and prenatal alcohol exposure. We further compared the association patterns and gender distribution of ADHD symptoms in children adopted from Poland to those reported in the literature for ADHD symptoms in non-adopted children. Dutch adoptive parents of 121 Polish adoptees (52% boys; M _age = 10.9 years, range 6.2–15.6; M _ageadoption = 3.0 years, range 0.8–6.9) completed questionnaires regarding ADHD symptoms, pre-adoptive risk factors, attachment problems, conduct problems, and executive functioning deficits. Bayesian evaluation of informative hypotheses showed that Polish adoptees had increased levels of ADHD symptoms, compared to Dutch children in the general population. Time in institutional care, early deprivation, and prenatal alcohol exposure were not associated with ADHD symptoms. ADHD symptoms in Polish adoptees were more strongly associated with attachment problems and executive functioning deficits, but less strongly with conduct problems, compared to ADHD symptoms in non-adoptees. Furthermore, ADHD symptoms were more equally distributed among boys and girls than they are in non-adopted children. The findings indicate that Polish adoptees and their adoptive parents need special attention and support. The dissimilarities between ADHD symptoms in Polish adoptees and non-adoptees might indicate a different underlying causal mechanism, which may have important implications for clinical practice.     

Action planning in young children's tool use

Tool use consists of at least two coupled phases of activities, involving multi-step problem solving. It therefore provides an interesting window on the development of planning in goal-directed behavior. This study investigated 2-year-olds' and 3-year-olds' hand use in picking up and subsequently using a tool for displacing a target-object towards a specified goal location. The children had to use a stick (Experiment 1; N = 41 in total) or a cane (hooked stick) that was lying in varying starting orientations (Experiment 2; N = 32 in total). Age differences were found in the way goal-related information in combination with tool-related information influenced the choice of which hand to use in different phases of the task. A view on action planning is developed as a dynamic action-selection process for which actions to take. This process integrates factors that are internal to the child's action system (e.g. motor preferences and dexterity) with external (i.e. sensory) sources of information.     

Learning new movement patterns: a study on good and poor writers comparing learning conditions emphasizing spatial, timing or abstract characteristics

In the earliest stages of motor-skill learning cognitive, visuo-spatial and dynamic processes play an important role. Which of these should be addressed first when children need to learn a new complex movement sequence? This study compares three learning methods in a within-subject design by having 18 good and 18 poor 8-year-old writers master unfamiliar, letter-like patterns by (1) tracing a trajectory on a screen, (2) tracking a moving target (pursuit), and (3) performing the pattern using written explicit instructions. Following each 10-trial learning phase, the children completed a short test phase. Besides errors and kinematic data, Dynamic Time Warping (DTW) was used to calculate the deviation for each pattern from the ideal shape (DTW-distance). As predicted, the number of errors and DTW-distance were very low during the learning phase of the tracing and pursuit conditions and higher in the explicit condition. Conversely, in the test phase, tracing yielded the highest DTW-distance and the explicit condition the lowest DTW-distance and error percentages. The results were remarkably similar for the good and poor writers. The poor learning results of the tracing condition and the good results of the explicit condition have important implications for the teaching of handwriting and remedial therapy.     

Communications About Environmental Risks and Risk‐Reducing Behavior: The Impact of Fear on Information Processing1

The present experiment examined the impact of fear on attitudes and the mediating role of information processing. Fear and argument strength were manipulated according to a 3 × 2 (Fear: Control vs. Moderate Fear vs. High Fear × Arguments: Weak vs. Strong) between‐subjects design. Fear was aroused with regard to the risks associated with global warming, and the information to be processed was a persuasive message about energy‐conserving light bulbs. The results indicate that both moderate and high levels of fear had an impact on attitudes. Moderate fear resulted in more positive attitudes toward energy‐saving bulbs, but only when strong arguments in favor of these bulbs were provided. High fear had a positive effect on attitudes, regardless of argument strength. It is concluded that fear may influence attitudes both in a direct and an indirect way, mediated by information processing. Whether the direct or the indirect effect dominates appears to depend on fear intensity.